根据地面塌陷寻找隐伏岩溶水的经验     

李德荣 《广东地质》2003,18(3):20-26

主要介绍在石灰岩分布地区广东省英德市寻找隐伏岩溶水的多种经验方法。根据地面塌陷的成因、特点以及找水标志，设计供水井位，寻找岩溶水，取得了较好的成果。研究和利用这些经验，对于寻找隐伏岩溶水具有较大的实际意义。  相似文献   

黑龙江省嫩江县三矿沟Cu-Fe-Mo矿床岩浆岩成因研究          下载免费PDF全文

李德荣  牛延宏  崔根  王秋阳 《中国地质》2016,(6):2104-2117

三矿沟Cu-Fe-Mo矿床是大兴安岭地区三矿沟—多宝山构造-成矿带中一个比较典型的矽卡岩型矿床。在大量野外地质调查、室内岩矿鉴定的基础上,对与成矿有关的三矿沟复式英云(花岗)闪长岩体的岩石地球化学特征进行了分析,探讨了该岩体的成因类型和构造环境。研究表明,该矿床岩浆岩体属于钙碱性I型花岗岩,具有大陆地壳的特征,形成于与造山花岗岩有关的火山弧环境或相似的构造环境中,主要与造山阶段的火山弧花岗岩关系密切。稀土元素配分图显示向右缓倾斜的轻稀土元素富集型特点,轻、重稀土分馏较为明显,无明显的负铕异常,暗示其具有相同或相近的成因,也反映了同源岩浆的特点。δEu值介于0.81~1.24,δCe值为1.00~1.13,表明岩浆演化过程中发生了微弱的分离结晶作用,同时又受到同化混染作用的一定影响,其成岩环境氧逸度较低,指示了缺氧环境,有利于金属元素的积聚而形成矿床。  相似文献   

线性预报方程中最优预报因子数的确定（续）     

Carr.  MB  周一鹤 《山西气象》1989,(3):52-59

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大地水准网的契比雪夫法平差     

Ebon.  MB 孙廷萱 《测绘译丛》1989,(4):28-33

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大地水准网的契比雪夫法平差     

Ebon.  MB  孙廷萱 《国外测绘》1989,(4):28-33

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A simple constant-head injection test for streambed hydraulic conductivity estimation   总被引：4，自引：1，他引：3  

Cardenas MB  Zlotnik VA 《Ground water》2003,41(6):867-871

A fast, efficient constant-head injection test (CHIT) for in situ estimation of hydraulic conductivity (K) of sandy streambeds is presented. This test uses constant-head hydraulic injection through a manually driven piezometer. Results from CHIT compare favorably to estimates from slug testing and grain-size analysis. The CHIT combines simplicity of field performance, data interpretation, and accuracy of K estimation in flowing streams.  相似文献   

试论不同力学性质的断裂构造的富水部位及富水性   总被引：15，自引：0，他引：15       下载免费PDF全文

李德荣  杨书安 《地质科学》1975,10(3):220-229

众所周知,断裂构造与地下水的关系相当密切。尤其是碳酸盐类岩石,岩溶极为发育并富含地下水,其原因在很大程度上与成岩以后的断裂构造有关。因此,研究不同力学性质的断裂构造的富水部位及富水性对于寻找地下水和查清矿区及各类工程的水文地质条件等,均有重要意义。  相似文献   

Persistent organic pollutants and stable isotopes in biopsy samples (2004/2006) from Southern Resident killer whales     

Krahn MM  Hanson MB  Baird RW  Boyer RH  Burrows DG  Emmons CK  Ford JK  Jones LL  Noren DP  Ross PS  Schorr GS  Collier TK 《Marine pollution bulletin》2007,54(12):1903-1911

“Southern Resident” killer whales include three “pods” (J, K and L) that reside primarily in Puget Sound/Georgia Basin during the spring, summer and fall. This population was listed as “endangered” in the US and Canada following a 20% decline between 1996 and 2001. The current study, using blubber/epidermis biopsy samples, contributes contemporary information about potential factors (i.e., levels of pollutants or changes in diet) that could adversely affect Southern Residents. Carbon and nitrogen stable isotopes indicated J- and L-pod consumed prey from similar trophic levels in 2004/2006 and also showed no evidence for a large shift in the trophic level of prey consumed by L-pod between 1996 and 2004/2006. ∑PCBs decreased for Southern Residents biopsied in 2004/2006 compared to 1993–1995. Surprisingly, however, a three-year-old male whale (J39) had the highest concentrations of ∑PBDEs, ∑HCHs and HCB. POP ratio differences between J- and L-pod suggested that they occupy different ranges in winter.  相似文献   

Effects of water use on arsenic release to well water in a confined aquifer     

Gotkowitz MB  Schreiber ME  Simo JA 《Ground water》2004,42(4):568-575

Field-based experiments were designed to investigate the release of naturally occurring, low to moderate (< 50 microg/L) arsenic concentrations to well water in a confined sandstone aquifer in northeastern Wisconsin. Geologic, geochemical, and hydrogeologic data collected from a 115 m2 site demonstrate that arsenic concentrations in ground water are heterogeneous at the scale of the field site, and that the distribution of arsenic in ground water correlates to solid-phase arsenic in aquifer materials. Arsenic concentrations in a test well varied from 1.8 to 22 microg/L during experiments conducted under no, low, and high pumping rates. The quality of ground water consumed from wells under typical domestic water use patterns differs from that of ground water in the aquifer because of reactions that occur within the well. Redox conditions in the well can change rapidly in response to ground water withdrawals. The well borehole is an environment conducive to microbiological growth, and biogeochemical reactions also affect borehole chemistry. While oxidation of sulfide minerals appears to release arsenic to ground water in zones within the aquifer, reduction of arsenic-bearing iron (hydr)oxides is a likely mechanism of arsenic release to water having a long residence time in the well borehole.  相似文献   

The use of the marine biotic index AMBI in the assessment of the ecological status of the Obidos lagoon (Portugal)     

Carvalho S  Gaspar MB  Moura A  Vale C  Antunes P  Gil O  da Fonseca LC  Falcão M 《Marine pollution bulletin》2006,52(11):1414-1424

This study reports the longitudinal distribution of sediment properties, including inorganic and organic contaminants, and the structure of the benthic community in Obidos lagoon, a coastal system permanently connected to the sea and with negligible freshwater sources. Sediments from the upper to central lagoon consist of fine particles (91%) and from the lower lagoon of sands (94%). Chemical composition is strongly correlated to the percentage of fine particles. Contamination is relatively low in those sediments suggesting the effect of diffuse sources. The increase in organic matter content from down- to upstream areas was associated with the dominance of opportunistic species, while sensitive and indifferent species to organic enrichment were mainly associated to the clean sandy downstream area. The marine biotic index (AMBI) was suitable for the discrimination of the biological and environmental gradients in the Obidos lagoon and was highly related with the gradient of organic matter content in this system.  相似文献